Window of opportunity for asthma

Changes in the gut microbiota have been implicated in the development of asthma in animal models; however, it has remained unclear whether these findings hold true in humans. Now, Arrieta et al. report in a longitudinal human study that infants at risk of asthma have transient gut microbial dysbiosis during the first 100 days of life. They found that certain bacterial genera were decreased in these children. Moreover, adding these bacteria back to germ-free mice decreased airway inflammation, suggesting a potential causative role of the loss of these microbes. They suggest a window where microbe-based diagnostics and therapeutics may be useful to prevent the development of asthma in high-risk individuals.